my 9 year is a handful

I have a 9 year old daughter who has gone thru sadness and turmoil in her life with me and her dad having a messy separation and divorce and not liking my ex partner who was strict which is something she doesn't like. since my ex partner walked out on us my daughter has changed. she has a bad attitude talks to people like dirt, she is very jealous of her brother who lives with his dad, also friends, she has problems making friends, she now says she is terrified of rain, wind and thunder but never has been also she is very clingy. i cannot talk on the phone without her listening and talking to me, i cannot go into another room with a friend to make a coffee without her around me, i am now in a new relationship with a wonderful man and my daughter says she loves him to bits but she wont even let us have two mins to ourselves while we are doing dinner. it is getting to me so much i feel trapped at the moment. she is very protective of me because of the hurt she has seen caused by her dad and my ex but trying to explain to her that i am ok now is very hard. i have support from close friends and family but they don't have her overnight for me and her father isn't much help. can anyone give me suggestions on what to do with her? i am under the doctor for stress now and she is not helping me at all.